Apparatus for drawing glass.



PATBNTBD AUG. 2, 1904.

J. H. LUBBERS. APPARATUS FOR DRAWING GLASS.

APPLIOATION FILED SBPT.6, 1899.

4 SHEETS-SHEET 2.

N0 MODEL.

Si ww www www INVENTQR PATENTED AUG. 2, 1904.

J. H. LUBBERS. APPARATUS. FOR DRAWING GLASS.

APPLICATION FILED BEPT.5. 1899.

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` N0.76G,275. PATENTED AUG. 2, 1904. J. H. LUBBERS. 1 APPARATUS EURDRAWING GLASS.

APPLlGTION FILED SEPT.5. 1899. l H0 MODEL. 4 SHEETS-SHEBT 4.

w'n'nssses I INVENTon chamber, partly broken away, and showing UNITEDSTATES Patented August 2, 1904.

PATENT OFFICE.

APPARATUS Fon DRAWING GLASS.

SPECIFICATION forming part of Letters Patent No. 766,275, dated August2, 1904.

Application filed September 5, 1899. Serial No. 729,436. (No model.)

being had to the accompanying drawings,` forming part of thisspecification, in which-' Figure 1 is a longitudinal section, partlybrokenaway, showing the drawing-chamber and leer of my improvedapparatus. Fig. 2 is a top plan View, partly broken away. Fig. 3 is avertical cross-section `through the leer, partly broken away,`to showthe drawingframe in its chamber. Fig. et is a cross-section of thedrawing-chamber, showing the sheet after it has been severed. Fig. 5 isa side elevation, partly broken away, showing the receiving-car at theend of the leer. Fig; 6 is a longitudinal vertical section of thedrawingmy preferred construction of muiile-walls; and Fig. 7 is adetail. end view of the baitholder. My invention relates to theformation o glass articles, such as sheets or cylinders, by drawing sucharticles from a body of molten l glass within a suitable furnace orchamber, and

it is designed to overcome thenumerous difficulties which haveheretofore prevented the obtaining of commercial glass sheets orarticles in this manner.

To that end it consists in shields arranged over the body of moltenglass and adapted to protect the bath at the point at which the sheet isdrawn from the surrounding heat;

further, it consists in a chamber into which portions, so as to preventwarping or bowing; also in devices for cutting off the lower end of thesheet from the bath after it has been drawn the desired length and in aleer which leads from the drawing-chamber and in which the glass isgradually annealed and cooled, so that it may be saved, and, further, itconsists in certain combinations and features ofcoustruction, ashereinafter more fully described, vand set forth in the claims.

In the drawings, in which I show my invention arranged for drawing glasssheets, 2 represents the end portion of a tank-furnace for making glass,and 3 an offset chamber or forehearth portion containing the moltenglass from which the sheets are drawn, the glass iiowing into thischamber from the main furnace ortank. In the roof of the chamber?) is atransverse slot or opening Within which are placed the tilting shieldsor partitions 4. 4, which normally extend downwardly to or nearly to thesurface of the molten glass. These shields, which are preferably ofrefractory material, are secured to transverse bars 5, projecting overthe roof, and they may be turned by levers 6, held in any adjustedposition by pins 7, placed in holesv in inclined braces 8. By this meansthe shields may be adjusted vertically to vary their distance above theglass-bath, and consequently the heat at the point of drawing the sheet.

In order to allow a more rapid drawing of the sheet than would otherwisebe possible, I preferably provide cooling devices, which in the formshown consist of U-shaped watercooling pipes 9, which rest upon theshields and swing therewith, these water-cooling pipes being providedwith suitable vinlets 10 and outlets 11, by which a continuous flow ofwater may be maintained therethrough. These cooling devices are not,however, necessary, though the drawing must be done more slowly if theyare not'used.

The glass-drawing operation is carried out between the shields by meansof aV bait 12,

which may consist of a piece of sheet-glass or a metal strip, the glasssheet, if such is used,

being clamped between the forked jaws 13 of -which contact with thebait, the jaws being drawn together by suitable bolts 14. The

` vertical bars 15 of the drawing-tool are joined by a transverse bar 18and are provided with upper oppositelyprojecting hooks 16 and with loweroppositely-projecting lugs 17.

In the drawing operation the hooks 16 are engaged by the spring-jaws 19of the drawingframe 20, this frame having a guide 21 at one end engaginga vertical strap in the end of the chamber 23 and rollers 22 at theopposite end, which contact with the walls, as shown in Fig. 3, thuskeeping the frame in the proper position during lifting. Thedrawing-frame is supported and moved vertically by chains or wire ropes24, which may pass over suitable pulleys to a winding-drum actuated inany desired manner.

The drawing-chamber 23, into which the sheet rises as it is formed, ispreferably made with hollow walls, forming muies, which are heatedbysuitable gas-burners 25, projecting into their lower portions, the amesand gases rising between spacing-bricks 26 'and .escaping throughsuitable outlet-ports 27 at the tops.

I have found in practice that where the horizontal zones of the drawingchamber are equally heated in a horizontal direction, as the edgeportions of the glass will cool more rapidly than the intermediateportion, the

` sheet Will be warped or curved, and to prevent this action Ipreferably form the drawing-chamber so that the sheet receives more heatin its outer portions than its intermediate portions, thusvcouvnteracting the quickery cooling of its-outer portions andpreventing warping or twisting of the sheet. Thus in Fig. 6 I show eachhollow wall or muiiie as provided with outwardly-inclined baiile platesor partitions 28.V .The burners 29 are locatedv at the outer sides `ofthese baffles, so that the rising heat-currents will heat the outerportions to a greater extent lthan the central or intermediate portions.This is an important feature of my invention, since if the heat is notapplied more to the edge portions than .to the intermediate partof thesheet the glass tends to warp, and I intend to cover the same, broadly,irrespective of the particular construction for obtaining this result.

The mulie-chambers may, if desired, be open at their lower ends, so asto receive the heat from the furnace and the extension thereof, and inany form the heat of the walls is gradually decreased upwardly, so thatthe temperature of the sheet will be graduallyreduced to preventbreakage during the setting or stiiening thereof.

The forehearth or extension 3 is preferably provided with endheating-burners 30 and a side burner 3l, these being employed to keepthe glass in the outer portion ofthe bath ofl comme the same consistencyor temperature as that in the inner portion next to the main tank. Thegases from these burners may be taken olf through a downtake-lne 32.

In the opposite sides of the chamber 3 and between the shields areprovided holes 33, through which asbestos-faced tongs 34 may beinserted. When the sheet. is being drawn, the operators insert thesetongs from time to time, as may be necessary, and seizing the edgeportions of the glass drawer stretch it outwardly, so as to keep thesheet oi' about the same width and prevent its narrowing down. Theseportions ol the sheet may be merely held against narrowing, if desired,though I prefer to positively pull or stretch the glass in a horizontaldirection. The upper end of the drawing-chamber is closed by hingedinwardly-projecting plates or dampers 35, which will swing' upwardly toallow passage therethrough of the drawing tool and frame.`

'In carrying out the drawing operation the bait-holder is lowered untilthe bait enters the bath and being heated thereby the glass will adhereto it. The holder is then slowly and steadily lifted, and as the baitrises the molten glass adhering to it will be drawn upwardly from thebath and assume the form of a sheet as it emerges, and this operation iscontinued until a sheet of the desired length has thus been drawn slowlyupward. The thickness of the glass sheet so formed is easily changed byregulating the temperature of the molten glass and changing the positionof the shields and the speed at which the bait is drawn upwardly.

After the desired length of sheet has been obtained it may be severedfrom the glass in the bath by means of shears 36, supported from asuitable hanger 37, moving on track 38, as shown in Fig. l, the shearsbeing'inserted through one of the holes 33, or, if de- IDO sired, thelower end of the sheet may be cut from the glass in the tank by liftingthe shields a short distance and allowing the heat or ames to cut offthe sheet near the level of the bath by a melting action, the shieldsthen being swung down to-their normal position.

As the sheet is drawn upwardly within the drawing-chamber itstemperature is gradually reduced and the sheet becomes set or stiffenedinto form. After it has been severed at its lower end it is lifted intothe position shown in Fig. 4and thence taken through an annealing-leer39. This leer connectswith one end of the drawing-chamber, and the leeris normally cut off from this chamber and itself separatedintodifferentchambers by horizontally-swinging dampers 40, provided 4with-'projectinglevers 41, connected by rod 42. These dampers are actuated by a cord43,- connected to one of the lever-arms and passing down over asuitablepulley 44. The

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lcer-walls are preferably made hollow and heated by suitable .burners45, which may be regulated so that the temperature will be graduallylowered as the glass sheerl is carried through the leer.

The top of the leer-chamber is closed by plates 46, a narrow slot beingleft between their inner ends for the passage of the sheetholder. Theleer is provided above the top of the annealing-chamber with parallellongitudinal bars 47, supported upon suitable hangers 48, with a narrowspace between them for the bait-holder. Below and in line with thesestationary bars are movable bars 49, having downwardly-projecting webswhich fit within grooved pulleys 50, carried upon shafts 51,

pivoted at their outer ends to brackets 52. These pulleys are movedvertically by bellcrank levers 53, having depending links provided withstraps taking about the inner jortions of the shafts. The bell-cranklevers are actuated by connecting-rods 54, the ends of which areconnected by chains 55 to sprocketwheels 56, secured to a common shaft57.

One of the wheels or pulleysis provided with a lever-arm 58, 'having adepending cord 59,

by means of which the shaft maybe rocked,

and the supporting-pulleys 50 thus raised or.

lowered simultaneously. The two movable bars are connected at theirouter ends by a' plate() and are moved longitudinallyover 'thesupporting-pulleys by a cord 6l, passing over a pulley 62. 4

After the drawn sheet has' been' cut off. and raised into the positionshown 'in Fig. 'l the .movable bars are slid forward on each side of thebait-carrier until thebars are beneaththe 'lugs 17. The' bait carrier orholder is then lowered to allow the lugs to rest on these bars and carrythe weight of the sheet and holder, the spring-jaws of the drawing-framespringing outwardly and releasing themselves from the hooks 16.` Thedampers 40 are then opened, and the movable bars arelifted and drawnrearwardly so as to bring the sheet into the rst'chamber of the leer.The pulleys 50 are then lowered, allowing the hooks' 16 of thebait-holder to rest on the stationary bars. The dampers are then closed.Another drawing-tool, with a bait clamped therein, is then hung on theframe 20, and the bait.

being lowered into the bath another sheet is drawn, as before. Themovable bars are again slid forward and engaged with the lugs 17 of thenext bait-holder. The pulleys and movable bars then being lifted andthe' dampers opened, the bars are'drawn rearwardly, thus bringing the-rst'sheet into the next chamber of the leer and the second sheet intothe first chamber. The dampers 40 are' then closed. Theseoperations'are'continued, and

the sheets as they emerge from the leer may be received upona car 63."(Shown in Fig.

l5.) This car is 'provided with supporting-l rods 64 for the glasssheets and with sepa- -ratus is provided by which sheets or other yrating-bars G5, which are wound with asbestos and project between thesheets. The baitholders are detached from the sheet at this point, thecarv being' moved along slightly as each sheet is inserted until itsinterior is filled, when it may be moved away and another car broughtinto position.

rlhe advantages of nay-invention will be apparent to those skilled inthe art, since appaarticles of'glass of an even thickness and fine nishmay be drawudirectly from a molten bath.

The advantages of my invention result from -the obtaining of a practicalapparatus by awaywith, ifv desired, the drawing-chamber may be heated inmany. other ways than that shown, the leer may be formed as an upwardextension of the drawing-chamber, the construction of the -leer .may bealtered, and many other changes may be made in the form and arrangementof the partswitho'ut departing from my invention;

l. In apparatusfor drawing glass, the combination with a chambercontaining molten glass,'of means for heating the same` ashield arrangedto protect the molten glass at the point at which the article is drawn,from the surrounding-heat, mechanism for drawing the glass upwardly outof contact with any forming-surface, and a drawing-chamber into which'the article passes as it is drawn; substan- 'tially as described.

2..'In sheet-'drawing apparatusifthe combination with a heatedchambercontaining molten. glass, of glass-drawing mechanism ar- IOO IIO

ranged to draw the glass upwardly out of contact with anyforming-surface, shields arranged to protect the glass at .the point atwhich the Iarticle is drawn, from the surrounding heat, and radiatingsurfaces arranged to artificially cool the article as it is formed;substantially as described'.

3. Inapparatus for drawing glass, the com- -bination .with a chambercontaining molten glass, of means for heating the same, a shield.arranged to protect the glass at the point at which the article isdrawn fromthe surround- 1 ing heat, a radiating device arranged to coolvthe article by.radiation or conduction as it is formed, and adrawing-chamber into which the article is drawn; substantially asdescribed.

4. ln apparatus for drawing glass, the comanism, vertically-adjustableshields arranged termediate portion; substantially as described.

combination with a chamber containing molten 'glass at the point wherethe sheet is drawn,

-bination with a chamber containing molten' glass, and glass-drawingmechanism arranged f to draw the glass upwardly therefrom out of;contact with any forming-surface, of a draw- Y ing-chamber into whichthe glass article passes, and which is arranged to retard itsA cooling;substantially as described.

5. In apparatus for drawingsheet-glass, the combination with achambercontaining molten f glass, and glass-drawing mechanism arranged to drawthe glass upwardly therefrom out of, Contact with any forming-surface,of a cham- 5 ber into which the sheet passes, said chamber beingarranged to retard the cooling of the? outer portions of the sheetrelatively to the in- 6. In apparatus for drawing glass, the combinationof a furnace or chamber containingf molten glass, glass-drawingrmechanism arranged to draw an article upwardly out of? contact with anyforming apparatus, and a; leer systemarranged to anneal the glass dur-1ing and after drawing; substantially as described.

7. In apparatus for drawing sheet-glass, the

glass and glass-drawing mechanism, of grip-` pers arranged to seize theedge portions of. the sheet toprevent'its narrowing; substantially asdescribed.

8. In apparatus for drawing sheet-glass, a chamber containing moltenglass, glassdraw-. ing mechanism, and grippers arranged to stretch theglass transversely as the sheet isi formed; substantially as described.

9. In apparatus for drawing glass, a chamber containing molten glass,glass-drawing mechanism, shields arranged to protect the from thesurrounding heat, and a drawingchamber arranged to retard the cooling ofthe glass and prevent breakage; substantially as described. l

10. In apparatus for drawing sheet-glass, a tank containing moltenglass, glass-drawing mechanism arranged to draw asheet upwardly out ofcontact with any forming-surface, a drawing chamber into which the sheetis drawn, and which is arranged to retard its cooling, and a leerextending from the drawing-chamber; substantially as described.

11. In apparatus for drawing sheet-glass, a chamber containing moltenglass, shields arranged to protect the glass at the point at which thesheet is drawn, a drawing-chamber into which the sheet passes, grippersarranged to seize the edge portions of the sheet to prevent narrowing,and a leer leading from the drawing-chamber; substantially as described.

12. In glass-drawing apparatus, a chamber containing molten glass,glass-drawing mechto protect the glass at the point where the drawing iscarried out, from the surrounding substantially as described.

heat and a drawing-chamber into which the article passes it is drawn;substantiallgY as described.

13. The combination with a chamber containing molten glass, means forheating thc glass in said cl'iamber, glass-drawing mechanism, swingingshields arranged to protect the glass at the point of drawing from theapplied heat, and mechanism for adjusting the shields to diiferentpositions; substantially as described.

14. The combination with a chamber containing molten glass, and meansfor heating the same, of glass-drawing mechanism, shields arranged teprotect the glass at the point of drawing from the applied heat, andwatercooled pipes arranged to cool the article as it is drawn;substantially as described.

15. In apparatus fordrawing sheet-glass, a chamber containing moltenglass, glass-drawing mechanism, and gripping-tongs arranged to beinserted through side holes in the chamber to hold the edges of thesheet; substantially as described.

16. In glass-drawingmechanism,a chamber containing molten glass, drawingmechanism arranged to draw the glass upwardly therefrom out of contactwith any forming-surface, and a vertically-extending drawing-chamberarranged to inclose the article as it is drawn upwardly; substantiallyas described.

17. rEhe combination with a chamber containing moltcn glass, and a glassdrawing mechanism arranged to draw the glass upwardly therefrom out ofcontact with any forming-surface, of a Verticallyextendingdrawing-chamber into which the article passes, and means for heatingsaid chamber to prevent sudden cooling of the glass; substantially asdescribed.

18. The combination with a chamber containing molten glass, andglass-drawing mechanism, of adrawing-chamber into which the articlepasses, said chamber having hollow walls` means for directing heatwithin the walls, and partitions arranged to heat the outer portions ofthe walls more than the intermediate portions; substantially asdescribed.

19. The combination with a chamber containing molten glass, of avertically-movable drawing-frame, a drawingtool detaehably supportedthereon, and a leer having supports for the drawing tool; substantiallyas described. l

20. In glass-drawing apparatus, the combination with achamber containingmolten glass, and glass-drawing'mechanism arranged to draw the glassupwardly therefrom out of contact with any forming-surface, of adrawingchamber into which the glass passes, said chamber being arrangedto retard the cooling, and shears arranged to sever the lower end of thearticle from the glass of the bath;

IOO

ILO

Q1. In apparatus for drawing glass,the combnation with a chambercontaining molten glass, and glass-drawing mechanism arranged to drawthe glass upwardly therefrom out of Contact with any forming-surface, ofa drawing chamber into which the glass article passes, and which isarranged to retard its cooling1 said chamber having hollow walls andmeans for introducing heat Within saidwalls; substantially as described.

In testimony whereof I have hereunto set my hand.

JOI-IN H. LUBBERS. I/Vitnesses:

MARsi-IALL H. RENO, L. A. CONNER, Jr.

